Transmission control mechanism



April 14, 1953 M. l.. GRIPE TRANSMISSION coNTRox. MECHANISM 2 sl-IEETs-SHEET 1 Filed Oct. 7, 1949 ATTORNEY April n14, 1953 y O M. L.. GRIPE 2,634,622

` TRANSMISSION CONTROL MEOHANISM Filed oct. 7. 1949 2 sHEETs-sHEET 2 50 0 |k l| y Z .Z915 92 9/ 7 46 i l 1 Y ..2 lg. /0\ 50 Z5 l INVENTOR. 94 M/gwELL L. CE2/PE ATTOENE' Y Patented Apr. 14, 1953 UNITED STATES PATENT OFFICE TRANSMISSION CONTROL MECHANISM Maxwell L. Gripe, South Bend, Ind., assignor to Bendix Aviation Corporation, South Bend, Ind., a corporation of Delaware Application October 7, 1949, Serial No. 120,175

(CI. 'i4- 335) i3 Claims.

This invention relates to power actuated mechanisms for selectively moving a control. element to one or the other of two operative positions, and more particularly to gear shifting mechanisms for operating the speed changing gearing commonly used in coupling the engine or prime mover with the driving wheels or the like of an automotive vehicle or the propeller. of a marine craft.

One of the objects of my invention is to provide-a power shifting mechanism for motor vehicle change speed mechanism, that is, electrical- 1y selective under the control of the driver.

A further object of the invention is to provide a compact, easily serviced, and relatively simple double acting electrically operated power unit well adapted for use in mechanism for operating the shiftable elements of the two speed axle structure of an automotive vehicle; and also well adapted to take the place of certain of the vacuum operated power units of the day now being used as a part of said mechanism.

Yet another object of my invention is to provide a double acting power unit, adapted for use in mechanism for operating the shiftable elements of the two speed axle structure of an automotive vehicle, including yieldable means connectible withl the axle structure said means comprising two yieldable members of different strengths one of said members serving to effect a. neutralization` of the axle structure and. the other member serving., by virtue-ofl its relative.- ly low factor of strength,l to effect a quiet Vmeshing of gears or equivalent members of said structure..

The other objects of the invention will appear more fully hereinafter from a consideration of the following description taken in connection with the accompanying drawings where one embodiment of the invention is illustrated by way of example.

Figure 1 is a diagrammatic view of parts: of an automotive' vehicle embodying the transmission operating mechanism of my invention;`

Figure: 2 is a view, largely' in section and taken on; the line 2--2 of Figure. 3, disclosing details of a preferred embodiment of the vpower unit of my invention;

Figure 3 is a sectional view, taken on the line 3--3 of Figure 2, disclosingk other details of the power unit of my invention; and v Figure 4 is a sectional view taken on the line 4-4 of'igure 3 disclosingv the stop means of the power unit of my invention. The transmission. operating power means constituting my invention is preferably employed to operate a two speed axle transmission mechanism of an automotive vehicle; however, it may be employed to operate any power transmitting mechanism of the power plant of a land or marine vehicle wherein said mechanism is selectively movable to two operative positions.

Referring to Figure 1 a transmission operating power unit l0 is detachably mounted on the carrier of what is known in the automotive art as a two speed axle, that is a part of the driving mechanism of the vehicle effectingY a gear' ratio in addition to the usual driving ratio and different therefrom. This two speed axle mechanism, actuated by the shifter mechanism of' my invention, is indicated by the reference numeral l2 and a change speed transmission mechanism cooperating therewith is indicated by the reference numeral Ui. The transmission operating mechanism constituting my invention may be employed to operate a Maybach clutch type of two speed axle, however, any other well known two speed axle construction is equally well operated by the mechanism of my invention. Y

There is disclosed, in Figures 2 to 4 inclusive, a. preferred embodiment of the power unit l0 of the transmission operating mechanism of' Fisure l, said unit constituting an important feature of my invention. Describing, this unit a casing t6 is shaped to receive a worm. gear I8 drivably mounted upon a shaft 20 journalled in bosses 22 and 22 constituting a part of the casing. The worm gear is dri-ven by a worm 24 drivably connected to a shaft 26; and this shaft is rotatably mounted, at its lower end 28, in the base of the unit. At its upper end the shaft 26 is preferably drivably connected to the shaft of a double field reversible `electric motor 36 of a well known. design.

As is disclosed in Figures 1, 2, and 3 the motor 30, which is grounded may be controlled by electrical means including, a manually operated single pole double throw selector switch 32' conveniently mounted on the control panel 34 within' the drvers compartment of the vehicle. The movable contact of the switch 52. may be electrically connected to a grounded battery 3l; and fixed contacts 38 and of' said switch are electrically connected, respectively, to a motor operated cut out switch 42. and a motor operated cut out switch of duplicate constructions, but undisclosed, positioned alongside the switch 112.` The latter switch preferably includes a xed contact 46 electrically connectechby a conductor 41, to the contact 3B of the switch 32; and the contact' it is preferably mounted: upon a. plate Iii! secured .to

the motor casing I6. The switch 42 also includes a movable contact 58, mounted upon a flexible support 50 secured to the plate 48; and the contact 58 is electrically connected, by a conductor 49, to one of the field windings of the motor 38. The aforementioned undisclosed switch, being a duplicate of the switch 42, is not described in detail herein. Suffice it to say that the movable contact of said switch is mounted upon a exible support member secured to the plate 48; and said movable contact is electrically connected to the other of the field windings of the grounded motor 30. The fixed contact, not shown, of the undisclosed switch is electrically connected, by means including a conductor 52, Figure 1, to the contact 40 of the selector switch 32.

Completing the description of the motor cut out switches the movable contacts thereof are biased into engagement with the fixed contacts of the switches. The means for operating the switch 42 and its companion switch positioned alongside thereof includes a cam 18, Figure 2, secured to an end portion of a cylindrically shaped rack member 54 slidably mounted within the casing I5. The outer surface of the rack 54 is provided with a groove 55 to receive a switch operating pin 58 and a switch operating pin 51; and as will be apparent from an inspection of Figure 2, lengthwise movement of the rack 54 serves, by the operation of the cam 18, to operate the switch 42 and the duplicate switch alongside thereof. The rack is moved to the right or left, Figure 2, by means of va pinion I I meshing therewith said pinion, as disclosed in Figure 3, preferably being integrally connected to the shaft 2U.

Describing now one of the important features of my invention, that is, the double acting yieldable force transmitting means interconnecting the motor driven Worm gear I8 and the two speed axle mechanism I2, a shifting fork, not shown, within the latter mechanism is yieldingly connected to the worm gear I8 by means including a hollow rod 16; The latter member is connected at one of its ends to the aforementioned shifting fork of the two speed axle mechanism, and within the hollowed out portion of its other end receives a connecting rod 11. VThe latter end of the rod 16 is slidably mounted within a thimble vmember 18 which fits tightly within the motor casing; and when so mounted the thimble and rod become a part of the motor unit I8. The inner end of the rod 11 is threadedly mounted within a tubular thrust member 14 which is received within the rack member 54. A spring 19, sleeved over the thrust member 14 and within the rack 54, is compressed between thrust washers 88 and 8I'. The washer 88 abuts a locking ring 82 secured to the rack 54 and preferably abuts a thrust washer 85; and the Washer 8l lpreferably abuts a flange 84 extending from and secured to the rod 11 and also abuts a locking ring 83 secured to the rackV 54.' A sleeve 54 is interposed between the flange 84' and a thrust Washer 81. A bolt 84 is threaded within the thrust member 14; and the thrust washer 85, sleeved over said bolt and interposed between a head portion 86 thereof and the washer 88 serves as a force transmitting member when the rack 54 is moved to the left, Figure 2.

Completing the description of the connection between the worm gear I8 and the shifting fork of the transmission, a spring 86a, sleeved over a Vtubular shaped stop Vmember 86', is com-V pressed between thrust washers 81 and 88 the latter member abutting a shoulder 89 of the rod 16 and the washer 81 a-butting a locking ring 98 embedded within one end of the rod 18. The spring 88a is preferably weaker than the spring 19 and the parts of the transmission operating mechanism of my invention are preferably so constructed and arranged that the springs 19 and 88a. are preloaded, that is, they are compressed when the mechanism is in its off, that is, transmission meshed position.

Describing now the means for stopping the movement of the rack 54 after the motor 38 is cut off there is provided a preloaded coil spring 9|, Figure 3, which is sleeved over the boss 22. One end of the spring rests upon a boss 92 secured to a wall portion of the casing I 6; and the other end of the spring rests upon a boss 93 also secured to a wall portion of said casing. A pin 94, secured to the worm gear I8, contacts lone or the other of the ends of the spring depending upon the direction of rotation of the gear, said spring serving to brake the rotation of the gear and bring the same to a stop. Preferably the parts of the mechanism are so constructed and arranged and so operative as to cut off the motor so as to limit the degree of compression of the spring 19; as to thecompression of the spring 86a this operation is limited by the operation of the stop 86.

Describing now the complete operation of the transmission operating mechanism disclosed in Figures 1 to 4, inclusive, it will be assumed that the vehicle is under way with the two speed axle mechanism I2 established in its low gear setting; and it will also be assumed when so established the parts oi' the mechanism assume the positions disclosed in the several figures of the drawings. In this position of the parts the motor cut off switch 42 is closed, the motor cut oif switch adjacent thereto is opened, and the parts of the yieldable connection assume the positions disclosed in Figure 2.

It will now be assumed that the driver of the vehicle has increased its speed, and that he desires a high gear setting of the transmission I2. To this end the driver will operate the selector switch 32 to select say the contact 38; and this operation closes an electrical circuit including the then closed switch 42. The motor 38 is thus energized resulting in a rotation of the worm gear I8; and the latter operation effects, through the intermediary of the force transmitting members 84' and 54 and by means of the operation of the rack 54 and pinion II, a compression of the spring 86a until the thrust washer 81 Iabuts, the stop 86', followed by a compression of the spring 19, the washer 88 leaving the washer 85. In this operation of successively compressing the springs 86a and 'I9 the switch 42 is opened, by the operation of the cam 10 in moving the pin 56 upwardly, to

cut off the operation of the motor 38; and the parts of the mechanism then in motion,.includ ing the worm gear I8 and parts connected thereto, are brought to rest by the operation of the stop spring 9|, Figure 3. In this regard the spring 9i is particularly useful when there is no resistance to movement of the rod 18 a condition which would exist if the motor is brought into play after the accelerator is released; for under these conditions it is quite necessary to provide some means for stopping the movement of the motor driven parts after the switch mechanismY has operated to cut on" the motor.

ANow it is apparent'from the above description that thishigh gear' operation 'of the 'selector "switch 32 andthe resulting compression of the springs 86a and 19 was effected prior to a release "of the accelerator of the vehicle; for this being expansion of the springs 19 and 86a to effect a lhigh gear operation of the transmission.

Continuing the description of the operation of the mechanism of my invention, t effect the latter setting of the transmission the driver will release the accelerator and this operation effects the necessary torque reversal operation of the power Iplant of the vehicle; for when the accelerator is released the internal combustion engine 95 of the vehicle no longer serves as a prime mover to load the gears or equivalent means of the transmission and thereby prevent a demeshing operatic-n thereof. It follows therefore that when the driver releases the accelerator the relatively heavy cocked spring '.19 becomes free vto expand to move the rod 16 to the right, Figure 2, to demesh the gears or their equivalent mechanism establishing the transmission in its low gear setting. The cle-meshing or oft called neutralizing operation of the transmission having been completed the next step in the operation is toefect'a synchronization of the gears to be meshed; and immediately after this operation is eiected the transmission is, by the expansion of the spring 86a, established in its high gear setting. It is to be noted that the latter operation is, by virtue of the expansion of the relatively light spring 86a, performed quickly and quietly.

Continuing the description of the operation of the mechanism of my invention, the transmission having been established in its high gear setting,

lthe accelerato-r may be operated in the usual manner to increase or maintain the speed of the vehicle. When a low gear setting of the transmission is desired the switch 32 is operated by moving the selective lever into engagement with switch contact 40 thereby completing the necessary electrical circuit to the motor 3); and as will .be apparent from the preceding description, this operation, assuming it is effected prior to the release of the accelerator or disengagement of the friction clutch, will effect an energization of the motor 30 resulting in a successive cooking of the springs Elta and 19, the rod Il moving to the left, Figure 2. As with the previously described high gear operation of the mechanism, the motor 30 is then automatically de-energized,

vafter thecam has moved a certain distance, by

an operation of the cut off switch mechanism; and the rotation, that is inertia effect, of the worm gear i8 is stopped 'by the operation of the spring 9|. In this motor cut off operation the cam 'lil moves the pin 57 to the position disclosed in Figure 2 thereby opening the cut off switch, not shown. A release of the accelerator toreverse the torque will then result in an expansion of the spring I9 to effect the desired neutralization .of the transmission and this operation is 'followed by a depression of the accelerator to synchronize the gears to effect the low gear setting or the transmission the latter operation being effected by the expansion of the spring 86a.

In the above described operation of cooking the springs the preloaded spring 86a is further compressed until the stop 86' contacts the washer S1; and after this operation is completed the preioaded spring 19. is. further compressed by the operation of the rack 54, the washer 8l leaving the locking ring 83.

There is thus provided, by the transmission operating unit lll together with the electrical controls thereof, an eieotve and efficient transmission operatine mechanism well adapted to quietly operate either a two Speed axle of an automotive vehicle or other change speed transe mission of the power plant of the vehicle... The motor unit it. constituting the essence of my in vention, includes relatively few moving parts preferably comprising a worm and worm gear mechanism driven by a double eld reversible electric motor thiS driving mechanism being connected to the transmission by yieldableforce transmitting means including two spr-ings C011.,- nected vin series. With this mechanism the timed cutting out oi operation of the electric motor, by the operation of the cut off switches, serves., in cooperation with the operation of the stop mechanism, to insure the desired inertia operation oi the moving parts to effect the desired comprese sion of the springs i9 and 86a; and with the mechanism of my invention the operation or the yieldable force transmitting means, positioned between the worm and worm gearvniechanism and the transmission, insures a relatively quiet operation of the transmission.

Although only one embodiment has been Iillustrated and described, various changes in the form and relative arrangements of the parts may be made to suit requirements.

I claim: l

1. A power unit for moving a control element from one to the other of two operative positions comprising a reversible motor, a force transmit; ting member driven thereby and drivably engag ing another force transmitting member, and a two-way force transmitting connection between the second mentioned force transmitting member and control element including a plurality of springs connected in series with each other and energized to move the element to one of its opera- .tive positions upon rotation of the motor in one direction and to its other operative position upon .rotation of the motor in the other direction.

2. A power unit for moving a control element from one to the other of two operative positions comprising a double acting motor, means for controlling the oper-ation of the motor, force. traIlS mitting means, including a plurality of series con,- nected springs, connected to the motor and en ergized upon venergization of the motor, .a ,motor shut-.off switch mechanism actuated by the motor and a connection from one sof the springs to the control element whereby the Spring, when energized, will move the element to one vOi? .its operative positions when the force resisting such motion is reduced to a value less .than thatbf the energized spring.

3. vIn a driving mechanism adapted to be incorporated in the drive system of an .automotive vehicle, the combination with a change Speed transmission including mechanism adapted to he established in at least two settings, of power "means for successively operating vthe transmission to establish rst one and then the other of the latter settingsy including a double -acting motor, force transmitting means interconnecting the motor and 'transmission' including two Yseries connected yieldable members operable to make `possible an operation of the motor, without in- -jury thereto, prior to either a demeshing or remeshing of the transmission, one of said two springs being compressed prior to a compression of the other spring and being operable to facilitate a quiet re-meshing operation of the transmission; together with means for controlling the operation of the m-otor.

4. In a driving mechanism adapted to be incorporated in the drive system of an automotive vehicle, the combination with a change speed transmission including mechanism adapted to be established in at least two settings, of power means for successively operating the transmission to establish first one and then the other of the latter two settings including a double acting motor, force transmitting means interconnecting the motor and transmission including a plurality of yieldable means operable to make possible an loperation of the motor, without` injury thereto, prior to either a de-meshing or re-meshing operation, and further operable to facilitate a quiet re-mesliing operati-on of the transmission; together with means for controlling the operation of the motor including a cut oi switch mechanism automatically operative, after a part of the force transmitting means has moved'a certain distance, to cut off the operation of said motor.

v5. In a driving mechanism adapted to be incorporated in the drive system of an automotive vehicle, the combination with a change speed transmission including means adapted to be established in at least two settings, of power means for successively operating the transmission to establish first one and then the other of the latter settings including a double acting motor comprising a power element, force transmitting means interconnecting the power element and transmission including successively operable springs connected in series and force transmitting means being operable to make possible an operation of the motor, without injury thereto, Vprior to either a de-meshing or a re-meshing op eration of the transmission and further operative to facilitate a quiet re-mesliing operation of the transmission, means for controlling the operation ofthe motor including a selector switch mechanism operative to initiate the operation of the V'motor V.and further including a cut oif switch mechanism automatically operative, after a part vof the force transmitting means has moved a cer- -tain distance, to cut oiT the operation of said 'motor; together with stop means operative to limit the rotation of the power element of the "motor after the cut on switch mechanism oper- 'at'es to de-energize the motor. 6. A power unit adaptable to operate a change 'speed-transmission of an automotive vehicle in- -cluding a motor comprising a drive shaft, a worm and worm gear unit operably connected to said jshaft, a transmission operating rod mounted in YV'the casing of the unit, and force transmitting Vmeans interconnecting the rod and worm ygear including a rack and pinion connection and fur- 'thef'in'cludinga plurality ofpreloaded andsuccessively operable springs connected in series with each other, said springs being stressed when the motor is energized to eiect an operation of 'the unit. V'7. A power unit adapted to operate a change speed transmission of an automotive vehicle said unit including an electric motor having Ia shaft, a casing, means within the casing comprising a `worm and worm gear drivenmechanism drivably 'connected to said shaft, a transmission operating rod, force transmitting means interconnecting the rod and worm gear including a rack and pinion connection and further including a plurality of successively operable springs connected in series with each other, said springs being energized when the motor is energized to effect an operation of the unit; cut `off switch mechanism for controlling the operation of the motor to limit the degree of energization ofthe spring, and means connected to the rack for operating the switch mechanism.

8. A power unit adaptable to operate a change speed transmission of an automotive vehicle including an electric motor comprising a drive shaft, a worm and worm wheel driven mechanism drivably connected to said shaft, a transmission v operating rod mounted in the casing of the unit,

force transmitting means interconnecting the rod and gear wheel including a rack and pinion connection and further including a plurality of successively voperable springs connected in series with each other, said springs interconnecting the rack and rod and being energized when the motor is energized to eect an operation of the unit, cut oi switch mechanism for controlling the operation of the motor to limit the degree of energization of the spring, means connected to the rack for opera-ting the switch mechanism, and sto-p means, including a part mounted on the worm gear, for limiting the movement of said gear wheel and the parts connected thereto, after the switch mechanism has operated to deenergize the motor.

9. A power unit adaptable to operate a two speed axle transmission of an automotive vehicle including, in combination, a double acting motor, force transmitting means connected to the power element of the motor, a transmissionvoperating rod, two separate double acting force transmitting means interconnecting the force transmitting means and rod including two successively operable springs which are compressed when the motor is energized, a motor operated cut off switch mechanism for in part controlling the operation of themotor to limit the degree of compression of one of said springs, and means, operable by one of the two double acting force transmitting means, for operating the switch mechanism. v

10. A power unit adaptable to operate a change speed transmission including a motor comprising a drive shaft, force transmitting means, including a rack and pinion, operably connected to the power element of the motor, cut 01T switch mechanism, actuated by the rack, for controlling the operation of the motor, a transmission operating rod, and force transmitting means interconnecting the rod and rack including two springs both of which are compressed, by an operationof the motor, to condition the same for a subsequent transmission operating operation of th rod.

11. A power unit adaptable to operate a change gear transmission including a double acting motor comprising a power, that is, driving element, force transmitting means connected to the lat- 'ter element, a transmission operating rod, and

force transmitting means interconnecting the rod and aforementioned force transmitting means including two successively operable springs connected in series with each other, one of said springs being weaker than the other and accordingly adapted to be cocked rst when the motor is energized and serving, after the other and heavier spring has effected a demeshing operation of the transmission, to effect a relatively quiet remeshing, that is, gear establishing operation thereof.

12. A power` unit adaptable to operate a change gear transmission including a double acting motor comprising a casing and a power element, force transmitting means connected to the latter element, a transmission operating rod, and force transmitting means interconnecting the rod and aforementioned force transmitting means including two springs connected in series with each other, one of said springs being weaker than the other and accordingly adapted to be cocked rst when the motor is energized and serving, after the other and heavier spring has effected a demeshing operation of the transmission, to eiect a relatively quiet remeshing, that is, gear establishing operation thereof; together with means for automatically cutting ofi the motor after a part of the latter force transmitting means has moved a certain distance, and means, including a yieldable member connected to the motor casing and a member connected to the first mentioned force transmitting means, for absorbing the kinetic energy of the moving parts of the motor and parts connected thereof, after the aforementioned cut o operation of the motor.

13. A preassembled unit for use in the transmission operating mechanism of an automotive vehicle comprising a casing, a motor housed 10 within the casing, a worm gear and a worm mechanism housed within the casing the Worm being drivably connected to the drive shait of the motor, a motor controlling cut off control mechanism within the casing, a rod slidably mounted in the casing, force transmitting means, including yieldable means and means for operating the control mechanism, interconnecting the rod and Worm gear and stop means housed within the casing and operable to limit the inertia movement of the Worm gear and parts connected thereto after the control mechanism is operative to de-energize the motor said stop means including a plurality oi members fixed to the casing, a coil spring mounted on one of said members and having one of its ends abutting one of said members and the other of its ends abutting another of said members, together with a pin connected to the Worm gear and adapted to abut one or the other of the ends of the spring in the operation of stressing the spring as it serves as a stop member.

MAXWELL L. GRIPE.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,268,264 Murray June 4, 1918 2,613,388 Lacey Sept. 3, 1935 2,426,234 Neracher et al. Aug. 26, 1947 2,462,779 Russell Feb. 22, 1949 

